Hex couplers are used to connect two pieces of threaded material. Hex and heavy hex couplers are threaded right hand. If a right hand-left hand coupler is needed, consider using a sleeve nut.

See our nut compatibility chart to determine the compatible hex coupler for a specific grade of bolt. Since hot-dip galvanizing typically adds 2.2 to 5 mils of thickness to the threaded portion of a fastener, galvanized couplers are tapped oversize to compensate for the corrosion resistant coating on the bolts.

Stock

Diameters: 1/2″ – 1″
Origin: Domestic and import
Finish: Black and hot-dip galvanized
Grades: A563 (grades A and DH)

Available

Diameters: 1/2″ – 6″
Origin: Domestic and import
Finish: Black and hot-dip galvanized
Grades: A563 (grades A, C, and DH), A194 grade 2H

Dimensions

Finished Hex Coupler Pattern

Click table to show drawingHex Coupling Nut
Nominal Size F C H Part Numbers
Width Across Flats Width Across Corners Length/Thickness Import
Basic Max Min Max Min Basic Max Min Black Galvanized
12 1116 0.688 0.663 0.794 0.756 134 1.760 1.690 12338 17525
58 1316 0.813 0.782 0.939 0.891 218 2.135 2.067 12559 18195
34 1 1.000 0.963 1.155 1.097 214 2.260 2.190 12557 17526
78 114 1.250 1.212 1.443 1.382 212 2.510 2.440 12558 19504
1 138 1.375 1.325 1.588 1.511 234 2.760 2.690 - 18494
118 112 1.500 1.450 1.732 1.653 3 3.010 2.940 18394 -
114 158 1.625 1.575 1.876 1.825 3 3.010 2.940 18994 17529
112 2 2.000 1.950 2.309 2.275 312 3.510 3.440 - -
Dimensions per ASME B18.2.2 2010
Some dimensions may vary by supplier

Heavy Hex Coupler Pattern

Click table to show drawingHex Coupling Nut
Nominal Size F C H Part Numbers
Width Across Flats Width Across Corners Thickness A563DH Domestic
Basic Max Min Max Min Basic Max Min Black Galvanized
12 78 0.875 0.850 1.010 0.969 112 - - - -
58 1116 1.062 1.031 1.227 1.175 178 - - 17543 17544
34 114 1.250 1.212 1.443 1.382 214 - - - 17527
78 1716 1.438 1.394 1.660 1.589 258 - - - -
1 158 1.625 1.575 1.876 1.796 3 - - - 12343
118 11316 1.812 1.756 2.093 2.002 338 - - - -
114 2 2.000 1.938 2.309 2.209 334 - - 17547 17548
112 238 2.375 2.300 2.742 2.622 412 - - 17551 17552
158 2916 2.562 2.481 2.959 2.828 478 4.91 4.83 - -
134 234 2.750 2.662 3.175 3.035 514 5.29 5.21 17553 17554
178 21516 2.938 2.844 3.392 3.242 558 5.67 5.58 - -
2 318 3.125 3.025 3.608 3.449 6 6.04 5.95 17555 17556
214 312 3.500 3.388 4.041 3.862 634 6.80 6.70 - -
212 378 3.875 3.750 4.474 4.275 712 7.55 7.44 - -
234 414 4.250 4.112 4.907 4.688 814 8.31 8.19 - -
3 458 4.625 4.475 5.340 5.102 9 9.06 8.94 - -
314 5 5.000 4.838 5.774 5.515 934 9.81 9.68 - -
312 538 5.375 5.200 6.207 5.928 1012 10.57 10.43 - -
334 534 5.750 5.562 6.640 6.341 1114 11.32 11.17 - -
4 618 6.125 5.925 7.073 6.755 12 12.08 11.92 - -
412 678 6.875 6.650 7.939 7.581 1312 - - - -
5 758 7.625 7.375 8.805 8.408 15 - - - -
Heavy coupler dimensions are not defined by ASME 18.2.2. The width across the flats and corners match the dimensions of a heavy hex nut.